(a) Field of the Invention
The invention relates to a positioning staple case of a stacker, and more particularly, to a positioning staple case of a stacker and having pressing strips pushed against by small springs, such that the pressing strips are horizontally displaced by pushing forces from the springs to lean against staples having various specifications using the pressing strips at various heights, thereby pressing the staples having different depths in a steady manner.
(b) Description of the Prior Art
During upholstery carpentry, an air stacker is generally used, so as to eliminate complications and inconveniences of manual stapling as well as to speed up a work process required.
However, boards that need to be assembled are assembled with various heights, and therefore staples needed also come in different depths. To place staples with different depths, a longitudinal recess having a staple case adjustment mechanism capable of adjusting pressing depths is provided. Using the staple case adjustment mechanism pressing against a row of staples, the staples are steadily pushed forward by means of a staple-pushing mechanism.
Yet, common staples exist in certain specifications only. Supposed a non-segmented method is adopted for pressing against the staples, it is necessary that adjustment be made each time a new row of staples is filled. Hassles are resulted whenever the staples are filled and thus causing inconveniences of users.
Referring to the Taiwan Patent Publication No. 424653 disclosing “Stacker Staple Gate”, the stacker staple gate comprises a right staple gate and a left staple gate. Wherein, the right staple gate has a stopping plate at a front end thereof and fastened using a sealing board, such that between the sealing board, the right staple gate and the stopping plate is a staple case. The right staple gate has a plurality of longitudinally penetrated sliding grooves, and an elastic pressing plate extended at a lower portion thereof. The left staple gate has a plurality of staggered spring-containing apertures penetrated through the left staple case and corresponding with the sliding grooves of the right staple gate. Each spring-containing aperture is disposed with an accommodating chamber penetrated through the left staple case, and is accommodated with a spring. Each spring has a top end thereof embedded into an upper pin, wherein a main upper pin of an adjacent groove is provided with a side aperture. The side aperture is for inserting with an L-shaped staple-pushing board having a wedge plane. An end face of an upper pin has an accommodating opening for inlaying an extension plate of the stopping plate. The stopping plate is placed in the accommodating chamber and is displaced upward by sliding movements using pushing forces of the spring. The extension plate of the stopping plate is formed as a retaining plane. The left staple gate has an aperture near an upper end thereof. The aperture is for retaining an L-shaped retaining staple-pushing board and a wedge plate of the staple-pushing plane to further prevent slipping off. A lower portion of the left staple gate is fixed with a sealing plate for sealing the lower portion of the left staple gate. The left staple gate is slid into the right staple gate, and is elastically embedded by the elastic pressing plate.
However, the individual pressing plates are independently pushed by the longitudinal springs, and perform back-and-forth sliding movements along the accommodating chambers of the left staple gate. Supposed staples having a smallest depth are placed, the staples are only pushed by one pressing plate. Or, if staples having a largest depth are placed, the staples are pushed by four pressing plates (as a quantity shown in the diagram). Therefore, the staples receive various pushing forces when staples having different depths are placed. When pushing forces received by the staples are unequal, pushing forces for pushing and cutting off the staples required by the staple-pushing mechanism are also different. That is to say, shearing forces from largest pushing forces for cutting off the staples having a largest depth are much too large for the staples having a smallest depth. Vice versa, shearing forces for cutting off staples having a smallest depth is insufficient for cutting off staples having a largest depth. Hence, the prior invention is hardly considered adequate when put to use, and can be further advanced.